package/siproxd: needs threads

siproxd which has been added with commit
3efc5a250c1c98598ba4c91a7d71d11343d937ab unconditionally uses pthread

Fixes:
 - http://autobuild.buildroot.org/results/828448fff87772e1c34b3696284a44eb9fc692fb

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Acked-by: Alexander Dahl <post@lespocky.de>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

package/siproxd/Config.in

@@ -1,5 +1,6 @@
 config BR2_PACKAGE_SIPROXD
 	bool "siproxd"
+	depends on BR2_TOOLCHAIN_HAS_THREADS
 	select BR2_PACKAGE_LIBOSIP2
 	select BR2_PACKAGE_LIBTOOL
 	select BR2_PACKAGE_SQLITE
@@ -15,3 +16,6 @@ config BR2_PACKAGE_SIPROXD
 	  masquerading firewall or NAT router.
 
 	  http://siproxd.sourceforge.net/
+
+comment "siproxd needs a toolchain w/ threads"
+	depends on !BR2_TOOLCHAIN_HAS_THREADS